Ascension : Met Office - Weather Report
Submitted by The Islander (Met Office) 15.12.2011 (Article Archived on 29.12.2011)

A mixed week with high pressure soon giving way to some deep low pressure systems from the Atlantic

Statistics for the week ending Monday 28-Nov-11

	Max (Celsius)	Min (Celsius)	Rainfall (mm)
AIRHEAD	28.0	20.1	4.0
TRAVELLERS	27.5	19.6	5.4
RESIDENCY	22.2	16.5	12.8
GEORGETOWN	29.3	20.8	1.5
ST. HELENA	19.9	13.2	2.8
FALKLANDS	16.6	1.3	6.5
UK (Brize Norton)	13.7	0.4	4.2

Past Week’s Weather

UK

A mixed week with high pressure soon giving way to some deep low pressure systems from the Atlantic. These passed by Scotland, bringing spells of rain and strong winds to most areas. Winds turned northwesterly later in the week, making for noticeably colder conditions and some sleet or snow in the north, especially Scotland and higher parts of northern England and Northern Ireland.

Falklands

A cool and rather unsettled week with winds generally from the west/southwest. Areas of low pressure passing to the south brought frontal systems and rain or showers, some of which turned wintry with some sleet or snow at times. High pressure built towards the end of the week, leading to more settled conditions.

Ascension

Another mixed week with varying amounts of cloud. Sunny periods were interspersed with cloudier, more showery and breezy ones.

St. Helena

Generally cloudy, but with a good deal of dry weather and just the odd light shower.

Interesting Missive, compiled by General C Nopsis

It’s almost impossible to predict the weather of the future without having a pretty good idea of what it’s doing right now (this relates to the infamous butterfly effect, whereby a small change in one place can lead to significant differences somewhere down the line). This is why we’ve spent centuries developing cleverer methods and instruments for observing the weather. As you’d probably expect, these include thermometers (temperature), barometers (pressure), anemometers (wind) and rain gauges; which is where most of the stats above come from. However, some of the less commonly known instruments include the multitude of satellites that sit many miles above us, watching, amongst other things, the cloud and moisture in the atmosphere. Most land areas (although, not Ascension) also have rainfall radar, and wind profilers to measure the wind speed up to tens of thousands of feet above the surface. Weather balloons supplement this data, giving us a better understanding of the structure of the atmosphere. And, you have to remember that what happens down here, is very much controlled by what’s going on way up there - through the troposphere (the part of our atmosphere up to around 40000 ft where most of our weather lives). All this is fed into supercomputers as trillions of calculations try to predict the future based on what’s happening right now. On top of this, Ascension, in its unique equatorial location, is one of a small number of sites worldwide that measure greenhouse gases, with the data used by researchers around the world aiming to better understand the warming that Earth is currently experiencing.

Crown Copyright 2011. Met Office.

Met Office  Ascension Island Base